Last July I began hooking up with a coworker. You could say we were friends first. We both agreed it was just sex; neither of us wanted a relationship. However, after five months (hooking up / sleeping over at each other's places usually three times a week) I started to fall for him, and I told him — at which point he suggested we end things, so we did.
About three months later, out of the blue, he asked me out again, and we picked up where we left off. It's not dating; we don't go out, I've never met his friends or family or vice versa — we just spend most nights together watching TV, talking, and having sex. It's been off and on for a year now and I don't want to ask for more for fear of him walking away again, so I tell myself I'm ok with it the way it is. However, I know my friends are wondering if this person actually exists... I don't think this is a 'normal' relationship, or a relationship at all, yet it is exhausting nonetheless.
What you’re describing is absolutely a relationship. It is a relationship where the man you’re seeing gets comfortable companionship on the couch and sexual gratification while your emotional desires are left unaddressed. Maybe you enjoy the companionship and sex too, but you’re clearly not getting everything you want from him. In the title of your email you asked how to define a non-relationship, and in this case I would define it as an unfulfilling one.
Unfortunately, this relationship pattern does happen. "Normal" isn’t quite the right word, but "common" does fit. You say you’re telling yourself you’re ok with the way things are, but you’re telling me you’re afraid to ask for the dates, shared social groups, and room to express romantic feelings that you want. Stop lying to yourself. Unless you want to remain in a relationship where you’re not getting your needs met, in which case I have no clue why you’re bringing this issue to me.
What I think you should do, though, is figure out what you want. What relationship label are you looking for, and what does that label mean to you? How much emotional attachment, security, and integration into each others’ lives do you need in order to have a relationship that feels healthy to you? Which desires are you willing to compromise on, and which ones are needs?
Then, sit down on that couch with the man you’re seeing and tell him what you want. If he wants to keep you around and cares enough to make the room for you in his life that you need, then by all means, keep working on it. If he suggests that you two end your relationship, end it. If he’s interested in making sure that your desires are met, be prepared to meet him in the middle — but make sure that you’re clear about which things you absolutely need. If he’s unable or unwilling to meet those needs, end it. If he behaves as though you’re being unreasonable by expressing your needs and desires, end it.
The thing to keep telling yourself is that you deserve relationships that increase your happiness and add joy to your life. You can’t force another person to meet your needs, but you can keep looking until you find someone who wants to meet them.
I strongly encourage you to see a doctor and discuss this with them. If your sexual response has decreased noticeably, it might have something to do with your hormones, or indicate some kind of physical condition. Also, discuss with your doctor the subtle diet changes you mentioned. What’s subtle to you might not be subtle to your body.
As far as sexual interaction between you and your partner goes, the most direct course of action would be to tell him your body is going through some changes you don’t currently understand and that you either need more sexual interaction before penetration, lube, or both. It kind of sounds like you’re trying to avoid the direct approach though, so here are some more subtle ways to encourage extended foreplay for you to consider:
Vocally responding to things you enjoy (with requests for him to continue doing whatever it is that he’s doing) as a form of positive feedback is one possible way to provide encouragement. Also, think about directly asking for new activities or more of whichever things he already does that you enjoy.
If you simply need more time for your body to naturally lubricate, think about putting focus on his physical pleasure while your sexual organs catch up. Touch all the parts of his body that make him feel good until you’re ready to be penetrated. Stroking his penis with your hands might be a good opportunity to get lube involved in a context other than “this is what I need to avoid abrasion burns in my vagina.”
Or, you could sneak away to squirt a bunch of lube in your vaginal canal and hope he’s not very observant. But, really, discussing what’s going on with you directly and honestly seems like the best option.